This book provides comprehensive sustainability assessment that justifies incorporating active disassembly in product design. It also presents design methodology to ease the design and innovation of active joints that provide active disassembly. Reader will be guided by a framework equipped with methods and tools that facilitate the process of incorporating active disassembly in product design. At the first level of the framework, comprehensive sustainability assessment models are developed to assess and justify the need for active disassembly. The first model assesses the opportunity to reuse an end-of-life product as a whole; while the second model assesses the opportunity to recover end-of-life product as assemblies and parts. The second level of the proposed framework is where active joint design method developed. The method, equipped with several tools, helps product designers design and innovate active joints for their products. The effectiveness and applicability of the developed assessment models and design method are validated through four industrial case studies.